DNS Management

Configure and automate DNS records with proper TTL strategies, DNS-as-code patterns, and troubleshooting techniques.

Purpose

Guide DNS configuration for applications, infrastructure, and services with focus on:

• Record type selection (A, AAAA, CNAME, MX, TXT, SRV, CAA)
• TTL strategies for propagation and caching
• DNS-as-code automation (external-dns, OctoDNS, DNSControl)
• Cloud DNS services comparison and selection
• DNS-based load balancing patterns
• Troubleshooting tools and techniques

When to Use This Skill

Apply DNS management patterns when:

• Setting up DNS for new applications or services
• Automating DNS updates from Kubernetes workloads
• Configuring DNS-based failover or load balancing
• Troubleshooting DNS propagation or resolution issues
• Migrating DNS between providers
• Planning DNS changes with minimal downtime
• Implementing GeoDNS for global users

Record Type Selection

Quick Reference

Address Resolution:

• A Record: Map hostname to IPv4 address (example.com → 192.0.2.1)
• AAAA Record: Map hostname to IPv6 address (example.com → 2001:db8::1)
• CNAME Record: Alias to another domain (www.example.com → example.com)
  • Cannot use at zone apex (@)
  • Cannot coexist with other records at same name

Email Configuration:

• MX Record: Direct email to mail servers with priority
• TXT Record: Email authentication (SPF, DKIM, DMARC) and verification

Service Discovery:

• SRV Record: Specify service location (protocol, priority, weight, port, target)

Delegation and Security:

• NS Record: Delegate subdomain to different nameservers
• CAA Record: Restrict which Certificate Authorities can issue certificates

Cloud-Specific:

• ALIAS Record: Like CNAME but works at zone apex (Route53, Cloudflare)

Decision Tree